The governor of Manus Island in Papua New Guina has told the country's parliament asylum seekers involved in last week's riot were transferred to the detention centre from Nauru.
But Australian Immigration Minister Scott Morrison says that is unlikely.
Manus MP, Charlie Benjamin, has denied local villagers were involved in an attack that claimed the life of a 23-year-old Iranian asylum seeker and he told PNG's parliament an investigation will reveal the source of the unrest.
The PNG and Australian governments have launched separate investigations into the riot amid conflicting reports of the location and nature of the riots that left dozens injured.
Mr Benjamin says some of the asylum seekers had been transferred from Nauru where they had been involved in the burning down of the detention camp in that country.